of the Red Beds themselves are its equivalents. The thickness of these basic rocks is very variable and attains its maximum in the Yangtze valley of Yunnan. While the Red Beds rest upon them in some localities, in others they were completely removed or were never present before their deposition. Huang, after noting that in the centre and west of Yunnan, the basic rocks are followed by Triassic Red Beds, suggests that the Liupakou Series "was actually replaced by basaltic lavas ".1 V. K. Ting, however, recorded Lyttonia, a common genus of the Lopingian, from below the lavas of the western part of the Tungchuan district of north-eastern Yunnan and, at first sight, it would appear, therefore, that these basic rocks are younger than the Liupakou Series, which hereabouts is largely absent. As the Lopingian is of Upper Permian age, according to Huang, the probability would then be, granting the existence of similar conditions over Central Yunnan, that the Red Beds are entirely confined within the limits of the Trias. This conclusion should not be lightly accepted for it assumes that the basic rocks in question are the equivalent of the Omeishan Basalt, and while this may be correct, there are, as I have pointed out in the last paper of this series, eruptive rocks in Yunnan both older and younger than the Omeishan Basalt. Even as regards the latter itself, H. C. T'an has recently stated:-" The time of the vulcanism is not strictly determined and it may be of Middle Permian age.' Again, Lyttonia though uncommon outside the Choutang Series has been recorded from below the Lopingian. Finally, as is shown in the next paragraph, the Upper Permian age of the Lopingian is not accepted by all authorities. 13 The coal-bearing, Gigantopteris Beds of Eastern Yunnan (the Liupakou Series), are succeeded as already mentioned, by thick, red, unfossiliferous sandstones and shales, often The Age of the Gigantopteris Flora and its impossible bearing on the Red Beds. to from the true distinguish Liupakou Beds themselves. This lithological resemblance naturally suggests a brief examination of the accepted position of the Chinese Gigantopteris flora in the geological scale. Palæobotanists including T. G. Halle, D. White, W. Gothan and H. C. Sze, as quoted by the last named, 1 Mem. Geol. Surv. China, Ser. A, No. 10, p. 70, [1932]. 2 Rec. Geol. Surv. Ind., Vol. 71, Pt. 2, p. 174, [1936]. 1 regard it as of Lower Permian age. T. K. Huang, however, places it in the Upper Permian on faunal and stratigraphical grounds, stating "The Gigantopteris Beds are simply the land facies equivalent of the Choutang Series which carries Lyttonia richthofeni " and, again, "The age of the Gigantopteris flora is undoubtedly Permian. It is contemporaneous with the Lyttonia richthofeni fauna (Choutang fauna) and slightly older than the Oldhamia decipiens fauna (Changhsing fauna). Its exact age, therefore, depends upon the age of these faunas. Noetling considered them Upper Permian, while Frech and Grabau took them as Middle Permian. Since Oldhamia fauna is the latest known Permian brachiopod fauna in China, the writer is rather inclined to follow Noetling's ideas."3 the I am greatly indebted to Prof. T. G. Halle of Stockholm for the following statement of his present view of this problem : "My first hand knowledge of the Gigantopteris flora is confined to North China. In 1927 I expressed the opinion that in Shansi this flora is not younger than Middle Permian and may fall entirely within the Lower Permian. Nothing has occurred since then to make me assign a younger age to this flora. We know little of the vertical range of Gigantopteris in South China, but judging merely from the fossil plants, I still think that the Gigantopteris flora is probably not younger than Middle Permian and may partly-even perhaps entirely-fall within the Lower Permian. I give you this opinion for what it is worth, fully realising that most geologists will let the marine faunas have the deciding vote."4 Correlation of the Lopingian with the Salt Range and Russian Permian. The Choutang Series and the Changhsing Limestone form the lower and upper divisions of the Chinese Lopingian and they were tentatively correlated by Huang with the Middle and Upper Productus Limestones, respectively, of the Salt Range, while the Lopingian as a whole was regarded as the equivalent of the Kama Beds and Tartarian Series of the Upper Permian of Russia. But there is an impressive body of opinion which does not accept these views, which would instead relegate the Choutang fauna, and, as a consequence, the Gigantopteris Bcds, to the Middle and in some cases to the Lower Permian. If this conclusion is correct, part of the Red Beds might well belong to the Upper Permian, but whether this will eventually prove to be the case still remains to be seen. Bull. Geol. Soc. China, Vol. XIV, No. 4, p. 569, [1935]. In a private letter, dated November 19th, 1937, According to G. Fredericks, the whole of the Lopingian is to be classified with the Kalabagh and Virgal Beds of the Middle Productus Limestone and with the Chernaya Ryechka Beds of Russia. The latter form the lowest of the three subdivisions of the Kungurian, itself the upper of the two divisions (Kungurian and Artinskian) of the Middle Permian, as defined by Fredericks.1 (Many Russian geologists of course still place these two divisions in the Lower Permian). Describing the Permian deposits of the Russian Far East which include limestones with Lyttonia, D. F. Masslenikov states that this fauna shows a close resemblance to that of Virgal and Kalabagh, as well as to the Chinese Lopingian and Maokou faunas, adding that. "Its composition indicates Middle Permian age, which corresponds to the upper parts of the Lower Permian by a binominal division of the system."2 Prof. J. A. Douglas in his analysis of the relationships between the Chinese, Indo-Iranian and Russian Permo-Carboniferous has suggested an emendation of Huang's correlation, and prefers to classify the Choutang Series with the Artinskian and the Changhsing Limestone with the Kungurian and the Upper Productus Limestone.3 Finally, A. W. Graban regards the Artinskian of Eastern Europe and the Lopingian of China as equivalent, retreatal phases of the same great marine transgression.4 It is noteworthy that the Lyttonia limestones of the Russian Far East are followed by freshwater, continental beds and Upper Permian shales with coal seams. We may also recall in this connection the occurrences of Red Beds with salt and gypsum in the Kungurian of European Russia, the Kazanian (Upper Permian) Red Beds of the Urals and the Ufa Plateau, the Vetlungian (Lower Trias) Red Beds of the Volga, Dvina and Oka regions as well as the characteristic features of the German Zechstein. "In China. too", as Grabau has remarked, “sandstones, often salt-bearing, represent a retreatal and partly emergent phase of the true Permian."5 1 Bull. Geol. Soc. China, Vol. XIII, No. 4, p. 546, [1934]. 2 Abstracts of Papers: XVII Internal. Geol. Cong., Moscow, p. 104, [1937]. 3 Pal. Ind., N. S., Vol. XXII, No. 6, p. 49, [1936]. 4 Bull. Geol. Soc. China, Vol. XV, No. 1, p. 43, [1936]. Ibid., p. 43. A. W. Grabau and V. K. Ting's Classifica of the Chinese tion Permian. Grabau's statement quoted in the preceding paragraph has been elaborated at length in his joint paper with V. K. Ting on the classification of the Chinese Permian, presented to the International Geological Congress at Washington in 1933, but not published until 1936, the year of Ting's lamentable death after a mining accident in Hunan. The earlier section of this paper in which it is shown that even under the earlier classification adopted by Huang and others, a place might still be found within the limits of the Permian for part of the Yunnanese Red Beds, was written before Grabau's and Ting's publication was available in England but is allowed to remain unaltered1. These authors place the whole of the salt-bearing Red Beds of Yunnan and Szechuan in the Upper Permian, mainly as a result of paleontological evidence, not at Huang's disposal, supplied by Prof. Etienne Patte's examination of faunas from Kueichow and elsewhere2. Their classification differs from Huang's by regarding his Uralian Series (the Chuanshian, which they rename the Mapingian) as Lower Permian; by raising the Yangsinian from the lower and lowering the Lopingian from the upper division and classifying them together as Middle Permian, and, finally, by creating a new division, the Yehlangian, of Upper Permian age. This Yehlangian Series, known only from South China, is stated to exhibit two distinct regional types; a north-western one confined to Yunnan, Szechuan and North-Western Kueichow and embracing the Lopingian (Gigantopteris) coal-bearing series with its overlying limestone and Red Beds a typical inland basin phase and a south-eastern, contemporaneous open sea phase, developed in South-eastern Kueichow and neighbouring regions. Huang, it may be recalled, regarded the Oldhamia Limestone as the upper limit of the Permian, mainly because of the striking faunal differences between it and the pelecypod beds still higher in the sequences, and on page 535 it has already been stated that Triassic lamellibranchs had been obtained from about the middle of the thick succession of red shales and sandstones above the Liupakou Series in Kueichow. 1 Rept. XVI Internat. Geol. Cong., Washington, Vol. I, pp. 663-674, [1936]. 2 Pal. Sinica, Ser. B, Vol. XV, Fasc. 2, [1935]. 3 Mem. Geol. Surv. China, Ser. A, No. 10, p. 101, [1932]. Prof. Patte has shown, however, that in strata overlying the Lopingian (Upper Permian of Huang) and particularly in the lower parts of the Yulungshan and Tayeh Limestones (Basal Trias of Huang, renamed the Sanchiao Limestone by Grabau and Ting), Paleozoic forms of life still persist. These include a trilobite, a new species of the entirely palæozoic ostracod Beyrichia, of the Palæozoic lamellibranch genus Protoschizodus together with the Permian form Pseudomonotis speluncaria Schl theim. This and other evidence detailed by Grabau and Ting led them to classify these beds, as well as the underlying Gastrioceras Shale as Upper Permian. In addition, they proceed further and classify the Feihsienkuan Series of North Kueichow and Szechuan as Upper Permian. As will be shown later (page 29), part of this series is undoubtedly of Werfenian age, but the horizons from which its fossils were derived lie within its upper portion and their discoverer, Dr. E. Wirth, was unable to decide whether the lower part belonged to the Trias or to the Permian.* Attractive as this classification is on broad, general grounds, it cannot even yet be taken as really proven that the salt-bearing Red Beds of Central Yunnan are contemporaneous with the fossiliferous Upper Permian of Kueichow. Plant Beds of the Reviewing now the evidence bearing on the age of the upper limit of the Red Beds of Central Yunnan, it has been suggested by Saurin that their upper horizons near LuChennan Chou District. fêng Hsien, pass laterally into Coal Measures which have yielded Rhætic or Norian palnt remains. The only other occurrence of this kind known to me in this part of the province, lies between Kaofungshao and Luhokai (Liho), four and eight miles, respectively, to the south-east of Chennan Chou. (Lat. 25°12′: Long. 101°15'). Here, dark, carbonaceous shales with thin partings of sandstone, black and greyish shales with broken plant remains and thick bands of coarse, white, friable sandstones, occur among typical members of the Red Beds. In an earlier report these were termed, "Deposits of Unknown Age to the East of Chennan Chou."1 though they are referred to 1 Rec. Geol. Surv. Ind., Vol. LIV, Pt. 1, p. 84, [1923]. * In a communication entitled :-" Yehlangian: Upper Permian or I ower Trias ? published after this paper was in print, T. H. Yin has severely criticised the views of Grabau and Ting. See Bull. Geol. Soc. China. Vol. XVII, Nos. 3 and 4, pp. 291-300, 1937. |